There are currently three studies within this project: 1) Transient kinetics of the sodium pump: Investigations into the cause of the biphasic characteristics of catalytic site phosphorylation and dephosphorylation, in collaborations with Froehlich, Fendler and Taniguchi. 2) Regulatory modifications of the sodium pump: Current studies are directed toward testing the hypothesis that the great sensitivity of P-type cation pumps to certain solvents is an "osmotic stress" effect on the accessibility of water to certain sites in these pump molecules. 3) Regulatory modifications of calmodulin-dependent kinase II: Studies of the functional consequences of the autophosphorylation states of calmodulin-dependent kinase II, in collaboration with A. Dosemeci.